Bhatkal, wanted in around 40 blast cases and carrying a reward of Rs 35 lakh, is the biggest IM leader ever arrested and security agencies are hopeful of gaining crucial information on the outfit that was designated a terrorist group in 2010.

On the run for over five years in several countries including Nepal, Bangladesh and Pakistan, Bhatkal (30) was held along with his associate Asadullah Akhtar aka Haddi (26) while crossing into India at Raxaul Nahar Chowk (around 100 km from Patna) opposite Birgunj town of Nepal.

“The arrest was carried out following a tip-off from central agencies and with the help of the National Investigation Agency (NIA),” Bihar additional director general of police (headquarters) Rabindra Kumar said in Patna on Thursday.

Bhatkal and his accomplices had been using the 750-km porous border of Bihar with Nepal to enter and exit the country in the last six months. The pattern was followed by the NIA and painstakingly put together, leading to the arrest, according to the police.

Hailing from Bhatkal town in Karnataka, the IM leader hit the spotlight after the 2008 Delhi serial blasts in which 30 people were killed.

Former home secretary RK Singh said Bhatkal had been the most active terrorist in the IM. “He himself was a bomb planter, organiser and was one of the most potent terrorists in that (IM) stable. We have been after him. Catching him, therefore, I think, is a great success.”

Singh added Bhatkal gave security agencies the slip at least twice earlier. “Once it was said he was arrested in Kolkata but they (security agencies) did not have his identity and he managed to get bail. On another occasion, our agencies had worked out a plan but he managed to give the slip.”

VIDEO: Shinde confirms Yasin Bhatkal's arrest

Bhatkal and Akhtar were produced before a court in Motihari and are to be brought to Delhi. This is the second major breakthrough for Indian agencies after the arrest of LeT bomb expert Abdul Karim Tunda on August 16.

The IM, patronised by Pakistan-based LeT, was designated a terrorist group by the government under the Unlawful Activities Prevention Act in June, 2010. The banned outfit was declared by the US as a Foreign Terrorist Organisation in 2011.